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| Study on mechanical properties of Beishan granite meso-heterogeneity under uniaxial compression with FDEM |
| ZHANG Shirui1，2，QIU Shili1，2，LI Shaojun1，2，LI Ping3，WANG Xu1，2，HU Xunjian1，2 |
(1. State Key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and Soil Mechanics，Chinese Academy
of Sciences，Wuhan，Hubei 430071，China；2. University of Chinese Academy of Sciences，Beijing 100049，China；3. College of Resources and Environmental Science，South-Central University for Nationalities，Wuhan，Hubei 430074，China) |
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Abstract In order to study the influence of the meso-heterogeneity on the initiation，propagation and coalescence of microcracks in Beishan granite，three types of meso-structure characterization models(cluster uniform model，Voronoi grain model and cluster tessellation model) were constructed based the combined finite-discrete element method(FDEM)、digital image processing(DIP) and grain based model(GBM). Based on the three types of models，uniaxial compression tests were carried out to study the influence of heterogeneity on the mechanics characteristics，acoustic emission(AE) characteristics and grain-scale crack propagation law. The research results show that three types of models can capture the evolution from micro-damage to macro-failure，intergranular tension cracks were firstly generated，then intragranular cracks were generated，and the cracks were mainly tensile cracks. The meso-structure characterizations effect significantly crack initiation stress(CI) and crack damage stress (CD). The AE characteristics of Voronoi grain model and cluster tessellation model were more consistent with the laboratory tests than cluster uniform model. With the increase of hard mineral content，the uniaxial compressive strength(UCS)，elastic modulus，CI and CD increased，but Poisson?s ratio decreased. With the increase of grain size，UCS and CD decreased. With the increase of stiffness heterogeneity factor，UCS，CI and CD decreased.
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2022, Vol. 41 
